Heretofore, difficulties have been encountered in the design of mechanisms for driving the feed of individual rounds of ammunition into the firing chamber area of automatic weapons. The feed and feed drive mechanisms had to be synchronized to the firing cycle demands of the weapon.
Prior attempts included spring loaded components or surfaces which subjected these feed mechanisms to vibrations or slippages due to external force loads to which the weapon was subjected, such as vibration effects if the weapon is vehicle mounted, and internal force loads such as recoil forces from the firing of the weapon. Such vibrations and slippages decrease considerably the synchronization of feed and weapon demand and, thus, the reliability of the weapon.
Other prior attempts to utilize cam devices synchronized to the movement of the recoiling parts of the weapon resulted in use of complicated reduction gear devices which not only added to the weight of the weapon but also reduced its reliability and introduced further problems of supply of additional repair and replacement parts.